The present invention relates to a manufacturing method of an optical fiber ribbon, in which a plurality of optical fibers coated with a resin are arranged in parallel to one another, and these respective optical fibers are fixed to one another intermittently along a longitudinal direction thereof.
An optical fiber ribbon for use in an optical fiber cable is one, in which an optical fiber strand or an optical fiber core wire is formed by coating outer circumferences of optical fiber bare wires (glass fibers) with a resin, a plurality of the optical fiber strands or the like are arranged in parallel to one another, and these are coated with a collective coating layer to be thereby formed into a ribbon shape. In such a way, work of connecting the plurality of optical fibers (optical fiber strands or the like) to one another collectively by fusion or connectors can be optimized.
With regard to the optical fiber ribbon formed by such collective coating as described above, a packaging density thereof is lowered by an amount of such a ribbon-like collective coating resin, and in addition, a bending direction thereof is regulated in terms of design of the optical fiber cable. Therefore, in particular, in an optical fiber cable with a relatively small number of core wires (approximately several ten core wires to hundred core wires), for which requests for a density increase and a diameter reduction are increased, the optical fiber ribbon is disadvantage in comparison with an ultimate packaging form with regard to such a density increase and a diameter reduction as in a simple aggregate of single core wires.
Therefore, for example, in an optical fiber ribbon described in Japanese Patent Laid-Open Publication No. 2010-33010, a plurality of optical fibers arranged in parallel to one another are fixed to one another intermittently (partially) along a longitudinal direction thereof, whereby the fact that the packaging density is lowered and that the bending direction is regulated is suppressed.
Manufacturing of the optical fiber ribbon in which the optical fibers are fixed intermittently to one another is carried out in such a manner that a plurality of optical fibers, which include resin coating layers and are arranged in parallel to one another, are sent out from optical fiber insertion holes open on an outlet surface of a coating dice. In this event, dam members such as shutters and discs are moved between the optical fiber insertion holes adjacent to one another, whereby ejection and damming of the resin for use in such intermittent fixation are carried out alternately.
However, in this case, there is an apprehension that, in the event of being sent out from the optical insertion holes, the optical fibers may be rubbed by outlet portions of the coating dice, and the resin coating on the optical fiber bare wires may be shaved off.
In this connection, it is an object of the present invention to suppress the coating resin from being shaved off in the event where the optical fibers are sent out from the coating dice.